Axial fluid flow machine such as a compressor or turbine



Sept. 5, 1967 A. BILL ETAL 3,339,833

AXIAL FLUID FLOW MACHINE SUCH AS A COMPRESSOR OR TURBINE Filed March 19, 1965 2 Sheets-Sheet 1 A. BILL ETAL Sept. 5, 1967 AXIAL FLUID FLOW MACHINE SUCH AS A COMPRESSOR OR TURBINE Filed March 19, 1965 2 Sheets-Sheet Z1 United States Patent 3,339,833 AXIAL FLUID FLOW MACHINE SUCH AS A COMPRESSOR 0R TURBINE Arthur Bill and Thomas Steel, Derby, England, assignors to Rolls-Royce Limited, Derby, England, a company of Great Britain Filed Mar. 19, 1965, Ser. No. 441,143 6 Claims. (Cl. 230-133) This invention concerns axial fluid flow machines such as axial flow compressors, turbines, fans and propellers, and machines provided therewith e.g. gas turbine engines.

According to the present invention there is provided an axial fluid flow machine comprising blades having root portions by which they are attached to a mounting member, the root portions of said blades being of dove-tail shape and being disposed within and extending radially through corresponding dove-tail slots in said mounting member such that the root portions project radially from a surface of said mounting member remote from the working positions of said blades, the projecting root portions of said blades being bonded to the said surface of said mounting member. The term blade used herein is intended to include vanes.

In a preferred embodiment, the root portions project from said surface of the mounting member for a major portion of their axial length.

The mounting member may be generally U-shaped in cross-section, the said root portions projecting through the base of said U-shaped mounting member.

The vanes or blades may be rotor blades, the mounting member being a rotor disc. Alternatively, the vanes or blades may be stator vanes or blades, the mounting member forming part of the casing of said machine.

The stator vanes or blades may also be bonded to an internal member, said internal member providing support for a rotor bearing of said machine.

The vanes or blades may be of metal or may be formed of fibre reinforced synthetic resin material. In a preferred embodiment the mounting member is also formed of fibre reinforced synthetic resin material, an adhesive being used to bond together the vanes or blades and said mounting member.

The vanes or blades may be compressor blades, the machine being an axial flow compressor.

The invention also includes a gas turbine engine provided with a compressor as set forth above.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which:

FIGURE 1 is a cut-away view of a gas turbine engine in accordance with the present invention,

FIGURE 2 is a part sectional view of part of the engine of FIGURE 1, taken in line 2-2 of that figure,

FIGURE 3. is a part sectional view of part of the components shown in FIGURE 2 taken in line 3--3 of that figure, and

FIGURE 4 is a general view of the components shown in FIGURES 2 and 3.

Referring to the drawings, a gas turbine engine includes a compressor 11 comprising rows of rotor blades 12, 13, 14, 15, rows of stator vanes 16, 17 and 18 and external casing 20. Rotor blades 12 and 13 are mounted on rotor discs 21, 22, attached to a rotor shaft 23. Rotor blades 14, 15 are mounted on rotor discs 24, 25 attached to rotor shaft 26.

Stator vanes 16 are disposed between the rows of rotor blades 12 and 13 and are connected to an external annular casing member 30, which forms part of the casing 20 of the compressor, and to an internal annular member 31. The annular member 31 is connected to a bearing 32 within which shaft 23 is journalled. Thus the row of stator vanes 16 supports the bearing 32 and the rotor shaft 23.

3,339,833 Patented Sept. 5, 1967 As more clearly shown in FIGURES 2 to 4, casing member 30 is substantially U-shaped in cross-section, having side walls 33, 34 and a base 35. An annular boss 36 is disposed between side walls 33, 34, on the external surface 37 of base 35.

Casing member 30 is provided with a plurality of axially extending, angularly spaced apart, dove-tail slots 38 within which are disposed corresponding dove-tail roots 40 of stator vanes 16. It will be seen that the roots 40 are somewhat larger, in radial dimension, than the base 35, they therefore project above the external surface 37. The roots 40 project above surface 37 for a major portion of their axial length and they define, with external surface 37, two angled portions 41, 42 in which bonding material (not shown) is disposed to bond the roots 40 to external surface 37. Thus the stator vanes 16 are A fastened to the external casing member 30 by their dovetail joints and by bonding material.

The compressor 11 may be formed of metal e.g. a light alloy, in which case the roots 40 may be bonded, brazed or welded to the external surface 37. Alternatively, the compressor 11 may be formed of fibre reinforced synthetic resin material, in which case the roots 40 are bonded to external surface 37 by an adhesive or by further fibre reinforced synthetic resin material fused to both the roots 40 and the external surface 37.

It will be appreciated that, since the roots 40 project through the casing member 30, and are visible from outside the casing 20 of the compressor, the bonding process may be performed after the vanes have been assembled. The bonding process is also relatively easy, since the surfaces to be bonded are readily accessible.

As seen in FIGURES 2 and 3, the internal annular member 31 is also substantially U-shaped in cross-section, having spaced radial flanges 50, 51 and a base 52. The annular member 31 is provided with a plurality of axially extending, angularly spaced apart dove-tail slots 54 within which dove-tail root portions 55 of vanes 16 are disposed. The root portions 55 also extend through the base 52 and project above the surface 56 of annular member 31, as described above with reference to roots 40 and member 30. Thus root portions 55 are bonded to the surface 56 by adhesive or by brazing or welding, for example, and by their dove-tail connections.

Although only the row of stator vanes 16 are attached to their supporting members by the particular dove-tail connections described above, it will be appreciated that any stator vane or rotor blade may be so connected to its supporting member. Thus stator vanes 17 and 18 may be connected to the casing 20 in this manner and rotor blades 12, 13, 14 and 15 may be connected to rotor discs 21, 22, 24, 25 respectively, in a similar manner.

Also, the same method of connecting blades to their supporting member may be used for any axial fluid fiow machine which uses bladed rotors and stators e.g. turbines, fans and propellers.

We claim:

1. An axial fluid flow machine comprising concentric inner and outer annular mounting members, angularly spaced apart dove-tail slots in each said mounting member, the slotsin one mounting member being inclined and oppositely disposed from the outer and inner sides of the support members with respect to the slots in the other mounting member, a plurality of radially disposed blades extending between said members, each blade having a working portion and having a root portion at each end thereof, the root portions of each blade being of dove-tail shape and being disposed within and extending radially through said dove-tail slots to lock and support the blades against movement radially and axially, said root portions projecting radially from the surfaces of said mounting members remote from the working portion of each blade,

and being bonded to the said surfaces of the mounting members.

2. A machine as claimed in claim 1 wherein said inner mounting member provides a bearing support.

3. An axial fluid flow machine as claimed in claim 1 in which said blades are stator blades and the said C011- centric mounting members comprise inner and outer stator casings.

4. An axial fluid flow machine as claimed in claim 1 in which the said mounting members are generally U- shaped in axial cross section.

5. An axial fluid flow machine as claimed in claim 1 in which said blades are formed of fibre-reinforced synthetic resin material.

6. An axial fluid flow machine as claimed in claim 5 in which said annular mounting members are formed of fibre-reinforced synthetic resin material and the projecting root portions of said blades are bonded to the said surfaces of the mounting members by adhesive.

References Cited UNITED STATES PATENTS 6/1950 Price 230133 6/ 1954 Wosika 25378 1/1959 Hampshire et al. 25377 5/1960 Warnken 253-77 7/1960 Stadthaus et al. 25377 8/1961 Warnken 25377 1/1964 Robinson et a1 238133 FOREIGN PATENTS 9/ 1952 Australia. 4/1960 Canada. 11/1951 Great Britain.

DONLEY J. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Assistant Examiner. 

1. AN AXIAL FLUID FLOW MACHINE COMPRISING CONCENTRIC INNER AND OUTER ANNULAR MOUNTING MEMBERS, ANGULARLY SPACED APART DOVE-TAIL SLOTS IN EACH SAID MOUNTING MEMBER, THE SLOTS IN ONE MOUNTING MEMBER BEING INCLINED AND OPPOSITELY DISPOSED FROM THE OUTER AND INNER SIDES OF THE SUPPORT MEMBERS WITH RESPECT TO THE SLOTS IN THE OTHER MOUNTING MEMBER, A PLURALITY OF RADIALLY DISPOSED BLADES EXTENDING BETWEEN SAID MEMBERS, EACH BLADE HAVING A WORKING PORTION AND HAVING A ROOT PORTION AT EACH END THEREOF, THE ROOT PORTIONS OF EACH BLADE BEING OF DOVE-TAIL SHAPE AND BEING DISPOSED WITHIN AND EXTENDING RADIALLY THROUGH SAID DOVE-TAIL SLOTS TO LOCK AND SUPPORT THE BLADES AGAINST MOVEMENT RADIALLY AND AXIALLY, SAID ROOT PORTIONS PROJECTING RADIALLY FROM THE SURFACES OF SAID MOUNTING MEMBERS REMOTE FROM THE WORKING PORTION OF EACH BLADE, AND BEING BONDED TO THE SAID SURFACES OF THE MOUNTING MEMBERS. 